The present invention relates to a method for enhancing the dewatering of sand through the use of various surfactants.
Crushed aggregate materials, such as sand or slag, and other materials which are handled as slurries, must be dewatered prior to subsequent handling.
Sand mines throughout the world process sand in a similar manner. A wet process is used to extract sand from the mine, and the sand is pumped to a processing facility. At the processing facility, sand and water are separated, and the sand is sized. Sand and water (about 85% solids) is then transported to a stockyard for storage and drying. Typically, a 15,000 ton sand pile drains down to about 3.5% moisture over about a 15 day period. The sand is processed in a furnace to evaporate the moisture to about 0.1%. Energy efficiency and productivity are important considerations in the mining industry.
The present invention provides a process to enhance the removal of water from wet sand in a sand dewatering operation. The present inventors discovered that the addition of an anionic or nonionic surfactant to a sand slurry prior to dewatering significantly reduced sand moisture after stack out.